HttpURLConnection does not support PATCH

[Maijh97]

Describe the bug

When DistroFilter forwards to the responsible node, if the http method is PATCH, an exception will occur: java.net.ProtocolException: Invalid HTTP method: PATCH.

Expected behavior
support forwarding requests with Http Method being PATCH.

Acutally behavior
A clear and concise description of what you actually to happen.

How to Reproduce
Steps to reproduce the behavior:

1. Cluster starts, three nodes.
2. Execute curl -X PATCH'http://127.0.0.1:8848/nacos/v1/ns/instance?port=8848&healthy=true&ip=11.11.11.11&weight=1.0&serviceName=nacos.test.3&encoding=UTF-8'

Desktop (please complete the following information):

• OS: MAC OS
• Version nacos-server 1.2.0 - 1.4.0
• Module naming
• SDK

Additional context
Add any other context about the problem here.